Push-button electrical switches

ABSTRACT

Each of the illustrated switches comprises a carriage in the form of a flat bar which is slidable through guide slots in a conductive body or bracket. A coil spring is mounted around the carriage and is connected between the carriage and the body. The contactor is secured to one side of the carriage and is engageable with the body. In one embodiment, the carriage is made of insulating material. In the second embodiment, an insulator is provided between the contactor and the carriage, which is made of metal. In both cases, the carriage can be made by an inexpensive stamping operation. The contactor is preferably in the form of a flat blade having a nose portion adapted to be moved into a slot in the body. The nose portion preferably has a pair of tapering edges which are engageable with the body at opposite sides of the slot. The wiping action between the tapering edges and the body insures that good electrical contact will be maintained between the contactor and the body. The contactor preferably has a terminal to which a flexible lead may be attached.

United States Patent Schink et al. [451 Apr. 25, 1972 [5 PUSH-BUTTONELECTRICAL Primary Examiner-J. V. Truhe SWITCHES Assistant Examiner-GaleR. Peterson 721 Inventors: William N. Schink, Crystal Lake; Harry J.Ammey aurme'ste" Palmauem Hamby Krol, Arlington Heights, both of ill.

[57] ABSTRACT Each of the illustrated switches comprises a carriage inthe form of a flat bar which is slidable through guide slots in aconductive body or bracket. A coil spring is mounted around the carriageand is connected between the carriage and the body. The contactor issecured to one side of the carriage and is engageable with the body. inone embodiment, the carriage is made of insulating material. In thesecond embodiment, an insulator is provided between the contactor andthe carriage, which is made of metal. In both cases, the carriage can bemade by an inexpensive stamping operation. The contactor is preferablyin the form of a flat blade having a nose portion adapted to be movedinto a slot in the body. The nose portion preferably has a pair oftapering edges which are engageable with the body at opposite sides ofthe slot. The wiping action between the tapering edges and the bodyinsures that good electrical contact will be maintained between thecontactor and the body. The contactor preferably has a terminal to whicha flexible lead may be attached.

6 Claims, 15 Drawing Figures PUSH-BUTTON ELECTRICAL SWITCHES Thisinvention relates to electrical switches and is particularly applicableto automotive-type switches, for use on automobiles, trucks and othervehicles.

One object of the present invention is to provide a new and improvedpush-button switch which is extremely reliable and serviceable, yet isunusually inexpensive.

A further object is to provide a new and improved push-button switch inwhich the body, carriage and contactor can all be formed by inexpensivestamping operations.

A further object is to provide a new and improved push-button switchhaving a contactor in the form of a flat blade arranged to provide awiping contact action with the body.

Generally, the present invention takes the form of a switch having abody with at least one guide opening therein. A carriage in the form ofa flat bar is slidable in said opening. A contactor is secured to oneside of the carriage and is engageable with the body adjacent theopening therein. A spring is provided to bias the carriage in onedirection.

Preferably, the carriage is in the form of a flat blade having at leastone tapering edge portion adapted to engage the body with a wipingaction. It is preferred to provide a pair of oppositely tapering edgeson the contactor, engageable with the body at opposite edges of theopening. The tapering edges are preferably formed on a nose portion ofthe contactor, such nose portion being movable into a portion of theopening.-

Preferably, the contactor includes a terminal adapted to receive aflexible lead. The opening in the body preferably comprises a largerportion for guiding the carriage and a smaller portion for receiving thenose portion of the contactor.

In one embodiment, the carriage is made of insulating material. In thesecond embodiment, an insulator is provided between the contactor andthe carriage, which is made of metal. In both cases, the carriage can bemade by an inexpensive stamping operation.

Further objects, advantages and features of the present invention willappear from the following description, taken with the accompanyingdrawings, in which:

FIG. 1 is an elevational view of a switch to be described as anillustrative embodiment of the present invention, the switch being shownin its closed position.

FIG. 2 is a view similar to FIG. 1, but showing the switch in its openposition.

FIG. 3 is an elevational view showing the opposite side of the switch. 7

FIG. 4 is a plan view, taken as indicated by the line 4-4 in FIG. 3.

FIG. 5 is a view similar to FIG. 4, but showing the switch in its openposition.

FIG. 6 is a fragmentary enlarged elevation, taken generally as indicatedby the line 6-6 in FIG. 3.

FIG. 7 is a sectional view, taken along the line 77 in FIG. 2.

FIG. 8 is a fragmentary enlarged longitudinal section, taken generallyalong the line 8-8 in FIG. 4.

FIG. 9 is an elevational view, similar to FIG. 2 but showing a modifiedswitch constituting another illustrative embodiment of the invention.

FIG. 10 is an elevational view showing the opposite side of the switchof FIG. 9.

FIG. 11 is a plan view, taken generally as indicated by the line l1ll inFIG. 10.

FIG. 12 is a fragmentary enlarged section, taken generally along theline I2-12 in FIG. 9.

FIG. 13 is a fragmentary enlarged section, taken generally along theline l313 in FIG. 9.

FIG. 14 is a view similar to a portion of FIG. 3, but showing a modifiedconstruction.

FIG. 15 is a section along the line l5l5 in FIG. 14.

It will be seen that FIGS. 1-8 illustrate a push-button switch which isespecially well adapted for automotive service. Thus, for example, theswitch 20 can be used as a warning light switch operable by a parkingbrake lever in such a manner that the light will be energized when thebrake is set, so as to warn the driver to release the brake before thecar is driven. The switch can also be used as a door operated switch toenergize the dome light, or any other desired lights, when the door isopened. The illustrated switch 20 is of the normally closed type, butthe invention is also applicable to push-button switches of the normallyopen type.

The switch 20 comprises a body of bracket 22 which supports a movablecarriage 24. It will be seen that the carriage 24 is in the form of aflat bar. Thus, the carriage 24 can easily be made by an inexpensivestamping operation. In this case, the carriage 24 is made of aninsulating material, such as a suitable resinous plastic material.However, the carriage 24 can also be made of metal, as will be disclosedin greater detail in connection with the second embodiment of FIGS.9-13.

At least one guide slot or opening is formed in the body 22 to receivethe carriage 24. In this case, the body 22 is formed with two arms 26and 28 having aligned slots 30 and 32. The carriage 24 is slidablyreceived in the slots 30 and 32. The illustrated body 22 is made ofsheet metal and can easily be formed by an inexpensive stampingoperation.

The carriage 24 is biased in one direction by a spring 34 connectedbetween the carriage 24 and the body 22. As illustrated, the spring 34.is in the form of a compression coil spring, mounted around thecarriage 24 and connected between the arm 28 and a shoulder 36 on thecarriage. The shoulder 36 is formed by an enlarged end portion 38 of thecarriage 24, serving as the operating push-button on the switch. Theenlarged portion 38 is slidably received in the slot 30 formed in thearm 26.

A contactor 40 is mounted on the carriage 24 and is engageable with thebody 22. At least the portion of the body 22 which is engageable by thecontactor 40 is conductive to form contact means. In this case, theentire body 22 is made of sheet metal and hence is conductive. Normally,the body or bracket 22 is secured to some portion of the metal body orframe of an automobile, and hence is electrically grounded to the frame.In virtually all automobiles, one side of the electrical system isgrounded to the frame. Thus, the switch 20 is particularly well adaptedto perform a switching operation in the ground side of a lamp circuit orthe like.

The illustrated contactor 40 is in the form of a flat plate or blade,secured to one side of the carriage 24 which insulates the contactorfrom the body 22 when the switch is in its open position, as shown inFIG. 2. The contactor 40 can be made very easily from sheet metal by aninexpensive stamping operation.

Various means may be employed to secure the contactor 40 to the carriage24. As shown, the contactor 40 has four tabs or flanges 42 which arewrapped around the rear end portion of the bar-shaped carriage 24. Thecontactor 40 also has a locating lug 44 which extends through an opening46 in the carriage 24. The lug 44 is preferably struck from thecontactor 40 and bent at right angles thereto.

The contactor 40 is preferably formed with a flat terminal or lug 48 towhich a flexible lead or wire 50 can be connected. A clip 52 is normallyconnected to the end of the lead 50 and is adapted to be mounted on theterminal 48. The lead 50 has sufficient length and flexibility toprovide for the longitudinal sliding movement of the carriage 24.

The contactor 40 preferably has a nose portion 54 which is movable intoa portion of one of the slots in the body 22. In this way, one or moreedges of the nose portion 54 are engageable with the body 22 at theedges of the slot. As shown in FIG. 7, the slot 32 is formed with sideportions 56 of reduced width to receive the nose portion 54. Thus, thecarriage 24 is slidable in the larger or main portion of the slot 32,which the nose portion 54 is movable into one of the reduced portions56. Two reduced portions 56 are provided so that the carriage 24 can bemounted in either of the two possible positions in the slot 32.

The nose portion 54 of the contactor 40 is preferably formed with atleast one tapering edge, adapted to engage the body 22 with a wipingaction. As shown, the nose portion 54 has a pair of oppositely taperingedges 58 which provide a balanced construction so that the nose portion54 is self-centering in the reduced slot portion 56. It will be seenthat the tapering edges 58 engage the body 22 at opposite edges of theslot portion 56. The nose portion 54, with its tapering edges 58,resembles a truncated arrowhead.

Due to the arrangement of the return spring 34, the pushbutton switch isnormally closed, in that the tapering edges 58 of the contactor 40engage the metal arm 28 of the body 22 at opposite edges of the slotportion 56. When the carriage 24 is pushed to the right, as shown inFIG. 2, the contactor 40 is moved out of the engagement with the body 22so that the switch is opened. The carriage 24, being made of insulatingmaterial, insulates the contactor 40 from the body 22.

When the pressure is released from the push-button portion 38 of thecarriage 24, the nose portion 54 enters the slot portion 56. Thetapering edges 58 engage the arm 28 of the body 22 with a wiping action.The tapering edges 58 cause the nose portion 54 to center itself in theslot portion 56. Due to the wiping action, the contacting surfaces ofthe contactor 40 and the arm 28 are kept clean so that good electricalcontact is maintained. Accordingly, the switch is extremely reliable andlong-lived. The contactor 40 is normally made of brass or the like, butthe body 22 can be made of ordinary sheet steel with zinc or cadmiumplating. The carriage 24 can be stamped from a phenolic sheet-material.Thus, all of the components of the switch are extremely low in cost.

FIGS. 9-13 illustrate a modified switch 60 which utilizes essentiallythe same body 22 as already described. However, the switch 60 has acarriage 64 which is stamped from sheet steel or some other sheet metal.The spring 34 is also the same as before. It will be seen that thespring 34 is compressed between the arm 28 and a shoulder 66 on thecarriage 64. As before, the shoulder 66 is formed by an enlarged endportion 68 on the carriage 64. The guide slots and 32 in the arms 26 and28 are the same as before, except that the slot 32 has only one reducedside portion 56.

The switch 60 comprises a contactor 70 which is very much the same asbefore, except that an insulator 72 is interposed between the contactor70 and the carriage 64. In the illustrated construction, the insulator72 is secured to the carriage 64, while the contactor 70 is secured tothe insulator 72. Various means may be employed to make theseconnections. As shown, the carriage 64 is formed with a lug 74 which isstruck from the carriage and bent at right angles thereto. The lug 74extends through a slot 76 in the insulator 72. The end of the lug 74 ispreferably staked to retain the insulator 72 thereon.

The illustrated contactor 70 is formed with two tabs 78 which extendthrough a pair of slots 80 in the insulator 72. The ends of the tabs 78are preferably staked to anchor them on the insulator 72.

Except as otherwise described above, the switch 60 of FIGS. 9-13 is thesame as the switch 20 of FIGS. 1-8. Similar components of the twoswitches have been given the same reference character, to avoid any needfor repeating the details of the description.

FIGS. 14 and 15 illustrate a modified construction, similar to that ofFIGS. 1-8, except that the lug 44 is replaced by a tubular extrusion oreyelet 144, formed from the metal of the contactor 40. The extrusion 144extends through a circular locating hole 146 in the insulating carriage24.

It will be evident that the switches of the present invention areespecially well adapted for use on automobiles as brake switches or doorswitches. When one of the switches is used as a parking brake switch, itis held open by the brake lever, or some other control member, when thebrake is released. When the lever is moved to its actuated position, theswitch is allowed to close by its own spring action, so as to energize awarning light or the like. In the usual arrangement, the warning lightis caused to flash, when energized, so as to warn the driver to releasethe brake before trying to drive the car. The

switch can also be arranged to operate by a brake pedal, so as toenergize the stop lights when the pedal is depressed.

When the switch is used as a door switch, the dome light or any otherlights in the automobile are energized when the corresponding door isopened. When the door is closed, it engages the carriage and moves thecontactor out of engagement with the grounded body.

The illustrated switches are normally closed when the pushbutton is notactuated. However, the invention is also applicable to normally openpush-button switches.

Various other modifications, alternative constructions and equivalentsmay be employed, as will be evident to those skilled in the art.

We claim:

1. An electrical switch,

comprising a body having a guide slot therein,

a flat bar-shaped carriage of rectangular cross-section slidablelongitudinally in said slot,

a spring biasing said carriage in one direction,

said body having stationary conductive contact means with an openingtherein adjacent said carriage,

and a thin flat contactor secured to one side of said carriage inparallel relation thereto and movable therewith,

said contactor having a thin flat blade-like nose portion of taperedwidth movable edgewise into said opening and having a pair of oppositelyslanting edges engageable with said contact means at opposite sides ofsaid opening, the opposite slant of said edges causing said nose portionto center itself in said opening to produce firm contact pressurebetween both slanting edges and said contact means,

the thin fiat construction of said nose portion and the edgewiseengagement between said slating edge and said contact means producingenhanced contact pressure therebetween.

2. A switch according to claim 1,

in which said carriage is made of insulating material to insulate saidcontactor fromsaid contact means except when said contactor engages saidcontact means.

3. A switch according to claim 1,

including an insulator mounted between saidv carriage and saidcontactor,

said carriage being made of conductive material.

4. A switch according to claim 1,

including a thin plate-like insulator mounted between said carriage andsaid contactor,

said carriage being made of conductive material.

5. A switch according to claim 1,

in which said opening merges into one side of said guide slot in saidbody,

said opening having a width which is less than that of said guide slot.

6. An electrical switch,

comprising a body having a guide slot therein,

an elongated carriage slidable longitudinally in said slot,

a spring biasing said carriage in one direction,

said body having stationary conductive contact means with an openingtherein adjacent said carriage,

and a thin flat contactor secured to said carriage and movabletherewith,

said contactor having a thin flat blade-like nose portion of taperedwidth movable edgewise into said opening and having a pair of oppositelyslanting edges engageable with said contact means at opposite sides ofsaid opening,

the opposite slant of said edges causing said nose portion to centeritself in said opening to produce firm contact pressure between bothslanting edges and said contact means, the thin flat construction ofsaid nose portion and the edgewise engagement between said slantingedges and said contact means producing enhanced contact pressuretherebetween.

* i 1F t

1. An electrical switch, comprising a body having a guide slot therein,a flat bar-shaped carriage of rectangular cross-section slidablelongitudinally in said slot, a spring biasing said carriage in onedirection, said body having stationary conductive contact means with anopening therein adjacent said carriage, and a thin flat contactorsecured to one side of said carriage in parallel relation thereto andmovable therewith, said contactor having a thin flat blade-like noseportion of tapered width movable edgewise into said opening and having apair of oppositely slanting edges engageable with said contact means atopposite sides of said opening, the opposite slant of said edges causingsaid nose portion to center itself in said opening to produce firmcontact pressure between both slanting edges and said contact means, thethin flat construction of said nose portion and the edgewise engagementbetween said slating edge and said contact means producing enhancedcontact pressure therebetween.
 2. A switch according to claim 1, inwhich said carriage is made of insulating material to insulate saidcontactor from said contact means except when said contactor engagessaid contact means.
 3. A switch according to claim 1, including aninsulator mounted between said carriage and said contactor, saidcarriage being made of conductive material.
 4. A switch according toclaim 1, including a thin plate-like insulator mounted between saidcarriage and said contactor, said carriage being made of conductivematerial.
 5. A switch according to claim 1, in which said opening mergesinto one side of said guide slot in said body, said opening having awidth which is less than that of said guide slot.
 6. An electricalswitch, comprising a body having a guide slot therein, an elongatedcarriage slidable longitudinally in said slot, a spring biasing saidcarriage in one direction, said body having stationary conductivecontact means with an opening therein adjacent said carriage, and a thinflat contactor secured to said carriage and movable therewith, saidcontactor having a thin flat blade-like nose portion of tapered widthmovable edgewise into said opening and having a pair of oppositelyslanting edges engageable with said contact means at opposite sides ofsaid opening, the opposite slant of said edges causing said nose portionto center itself in said opening to produce firm contact pressurebetween both slanting edges and said contact means, the thin flatconstruction of said nose portion and the edgewise engagement betweensaid slanting edges and said contact means producing enhanced contactpressure therebetween.